Patent attributes
A lock device for preventing rotation of a rotating portion of a piece of furniture includes a positioning device, an engaged portion, an engaging portion, a biasing element, and an operation lever. The engaging portion is rotatable around an axis parallel to a rotating axis of the rotating portion, and is engageable with the engaged portion when the rotating portion is in a position positioned by the positioning device. The engaging portion includes at least one engaging surface engageable with the engaged portion. The engaged portion includes at least one engaged surface engageable with the engaging portion. The at least one engaging surface is rotated while being moved in a direction of departing from the engaged surface in accordance with a rotation of the engaging portion by the operation lever.